1. Field of the Invention
The present invention relates to an angular velocity sensor element for detecting the angular velocity of an object.
2. Description of the Related Art
Angular velocity sensor elements have been used in techniques for autonomic control of the attitudes of ships, airplanes, rockets, etc. In recent years, incorporation of angular velocity sensor elements into small electronic appliances such as vehicle navigation systems, digital cameras, video cameras and portable telephones has been put into practice. With the trend, a demand has arisen for further reducing the size and thickness of angular velocity sensors.
On the other hand, making of a vibrating arm of a vibration-type angular velocity sensor is being widely performed by cutting and forming a piezoelectric material by means of machining. Naturally, there is a limit to the accuracy of machining for making such a component. It is, therefore, difficult to meet the above-mentioned demand for further reductions in size and thickness.
A technique to form a vibrating arm by finely working a single crystal thin plate has been proposed with the aim of further reducing the size and thickness of angular velocity sensors. For example, an angular sensor element including an element with a vibrating arm and affixing portion in frame form fixed to the element is disclosed in FIG. 21 of Japanese Patent Laid-Open No. 11-72334.
However, when a sudden impact is applied to such an angular sensor element from the outside, vibration due to this impact is transmitted from the fixing portion to the element portion to be detected as noise through the vibrating arm of the element portion in the detection system.